Bougainville may seek arbitration if the Papua New Guinea Government does not pay what it says are outstanding grants of $US143 million dollars.President John Momis, who was sworn in for a second term at the beginning of the week, says the money is guaranteed under the Bougainville Peace Agreement which formally ended the ten-year long civil war.He says the Restoration and Development Grants are vital for the region as it tries to develop its economy ahead of the referendum on independence that is due before 2020.PNG has in recent years contributed other funds to Bougainville, but Mr Momis told Don Wiseman that money is tied aid but the Restoration and Development Grants are different.